There are many containers or cans manufactured daily that are filled and then sealed with a can end or lid. These container lids are provided with pull tabs for forming an opening in the container lid which opening in the container lid is defined by a score line. The pull tabs may be of the stay-on-tab style, the throw away tab style, the complete panel removal style and other styles. In all instances, it is desired that there is some resistance to moving the pull tab to form the opening in the container lid but not so much resistance that the opening is too hard to form or cannot be formed or too little resistance that the container lid will prematurely open. In order to ensure customer satisfaction in the forming of openings in the container lids, it is customary to test daily many thousands of container lids to ensure that the manufacturing apparatus for making the container lids is functioning properly. One testing apparatus is marketed by Continental Can Co. and comprises a hand operated device which is subject to human operational variances. There exists a need for apparatus which would function to operate on each container lid to be tested in the same manner so that consistent test results could be obtained.